By Sharon Atieno
In a first of its kind, a new study has provided evidence of African children with severe malaria experiencing partial resistance to the world’s most powerful malaria drug- artemisinin.
The Ugandan study presented at the Annual Meeting of the American Society of Tropical Medicine and Hygiene (ASTMH) and published in the Journal of the American Medical Association (JAMA), documented partial resistance to artemisinin in 11 of 100 children, ages 6 months to 12 years. They were being treated for “complicated” malaria- cases where the disease is at risk of causing potentially life-threatening complications, like severe anemia or brain-related problems known as cerebral malaria.
Also, 10 patients who were thought to have been cured suffered a repeat malaria attack within 28 days from the same strain of malaria that caused the original infection, suggesting that the initial treatment did not fully kill the infecting parasites.
The Ugandan children in the study received what is considered to be the gold standard for treating complicated malaria infections: an intravenous infusion of artesunate followed by oral treatment with an artemisinin combination therapy (ACT) that combines another derivative of artemisinin, a drug called artemether, with the malaria drug lumefantrine.
These findings are particularly alarming given that Africa bears the biggest burden of malaria. In 2022 alone, Africa accounted for nine out of ten (about 233 million) malaria cases in the world. Of the 580,000 malaria deaths recorded in the region in this period, children under five years accounted for four in five.
Artemisinin therapies have been in use for about 20 years rapidly curing infections and acting as an alternative for dealing with malaria parasites developing resistance to other drugs.
In 2008, there were reports from Cambodia noting partial artemisinin resistance. By 2013 there was evidence that in some patients, the drug was completely failing. In the last few years, there has been increasing evidence that artemisinin resistance has now spread from that region into East Africa.
While all of the children in the study eventually recovered, 10 of them were infected with malaria parasites that harbor genetic mutations that have been linked to artemisinin resistance in Southeast Asia.
The study noted that while these mutations have been documented in Africa in less severe cases, this was the first time they had been seen in parasites causing complicated malaria in hospitalized African children.
According to Chandy John, the study’s co-author and director of the Indiana University School of Medicine Ryan White Center for Infectious Diseases and Global Health, the path to broadly resistant malaria parasites in Southeast Asia started with evidence of partial artemisinin resistance. He is concerned that this pattern will be repeated in sub-Saharan Africa.
John said the relatively high number of recurrent cases raises concerns that the efficacy of lumefantrine may also be declining. The drug is paired with artemether to make it harder for parasites to develop artemisinin resistance and because lumefantrine stays in the body longer than artemether. Therefore, it can kill any remaining parasites not cleared by the shorter-acting artemisinin.
Other authors include Ruth Namazzi and Robert Opoka from Makerere University in Kampala, Uganda, Ryan Henrici from the University of Pennsylvania, and Colin Sutherland from the London School of Hygiene & Tropical Medicine.
